As is well known to those skilled in the art, water cutting systems are utilized in a wide variety of industries to effect cutting of metals, plastics, and other materials. In the operation of a water cutting system, water at extremely high pressure, e.g., 50,000 psi, is directed through a nozzle which forms the water into a very small diameter, very high velocity stream. The nozzle typically comprises a jewel selected from the group consisting of diamonds, sapphires, and rubies. The jewel has a very small diameter orifice formed therethrough. For example, the diameter of the orifice formed through the jewel is typically between about 0.0004 inches and about 0.0016 inches.
Heretofore the jewels comprising the nozzles of water cutting systems have been mounted in nozzle support structures formed from stainless steel or other metals that are not subject to deterioration caused by exposure to water. A water discharge passageway extends through the support structure and a jewel receiving cavity is formed at the water receiving end of the water discharge passageway. The jewel comprising the nozzle of the water cutting system is mounted in the jewel receiving cavity and is retained either by a suitable adhesive or by positioning the jewel in a band of soft metal such as brass and then pressing the band of soft metal having the jewel retained therein into the jewel receiving cavity.
The jewel comprising the nozzle of the water cutting system has a locating surface comprising the inner end thereof. The jewel receiving cavity has a locating surface comprising the bottom thereof. Engagement between the locating surface of the jewel and the locating surface of the jewel receiving cavity is necessary to assure proper alignment of the orifice extending through the jewel.
As will be understood, the locating surfaces comprising the interior surface of the jewel and the bottom surface of the jewel receiving cavity must be entirely smooth, flat, and free of any radially extending grooves or ridges. Otherwise the water passing through the water discharge passageway of the support structure will enter the space between the bottom of the jewel receiving cavity and the interior surface of the jewel with the result being degradation of the locating surfaces and misalignment of the jewel within the jewel receiving cavity. However, because the locating surface of the jewel receiving cavity is located at the bottom thereof, consistency in providing the jewel engaging surface with the required surface finish has been difficult to achieve.
The present invention comprises a method of and apparatus for mounting the jewels which comprise the nozzles of water cutting systems which overcome the foregoing and other difficulties which have long since characterized the prior art. In accordance with the broader aspects of the invention a structure for receiving and positioning a jewel comprising the nozzle of a water cutting system includes two components. A first component has a water discharge passageway extending therethrough. The water discharge passageway extends from a jewel engaging exterior locating surface. Because it comprises an exterior surface of the first component, lapping the locating surface to achieve the required surface finish of less than 8 RMS is straightforward. Manufacturing techniques other than lapping which provide the necessary surface finish can also be used in the practice of the invention.
The second component of the jewel receiving and positioning structure comprises a chamber which receives the first component therein. The second component has a water directing passageway formed therein which extends to a jewel receiving cavity. A jewel comprising the nozzle of the water cutting system is received in the jewel receiving cavity of the second component with the locating surface thereof mounted in engagement with the exterior locating surface of the first component. Because the jewel is trapped between the first and second components of the support structure, the use of either an adhesive or a metal band to retain the jewel in the jewel receiving cavity is eliminated. Precise machining of the interior surfaces of the jewel receiving cavity is unnecessary since the positioning of the jewel is not dependent on the interior surfaces of the cavity but instead depends upon the engagement of the locating surface of the jewel with the exterior locating surface of the first component of the support structure.